99 research outputs found

    About quantitative EBSD analysis of deformation and recovery substructures in pure Tantalum

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    International audienceThe aim of this work is to present a quantitative analysis of features involved in recovery during annealing of deformed Tantalum. In pure metals where crystalline defects usually have high mobility, dislocation annihilation and rearrangement occur to a great extent prior to recrystallization. Therefore a complete understanding of recrystallization cannot be accomplished without an advanced knowledge of the recovery phenomenon. Depending on whether dislocations induce a measurable curvature in the crystal lattice or not, they are called Geometrically Necessary Dislocations (GNDs) or Statistically Stored Dislocations (SSDs) respectively. In the present work only GNDs are considered. For this purpose electron backscatter diffraction (EBSD) is an advantageous technique to obtain statistically representative results when compared to Transmission Electron Microscopy (TEM). However, a quantitative analysis of GNDs from EBSD data is not straightforward. Since local misorientations are induced by the curvature of the crystal lattice caused by GNDs, GNDs analysis can be done using local misorientations. However the values obtained from this analysis are step size dependent and influenced by the measurement noise. Reasoning on the basis that when the step size tends to zero, local misorientation should also tend to zero, measurement noise can be estimated [1]. The measurement noise appears to notably be very much dependent on the amplitude of local misorientations, which must be considered in the perspective of GND density calculatio

    Resolving XML Semantic Ambiguity

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    ABSTRACT XML semantic-aware processing has become a motivating and important challenge in Web data management, data processing, and information retrieval. While XML data is semi-structured, yet it remains prone to lexical ambiguity, and thus requires dedicated semantic analysis and sense disambiguation processes to assign well-defined meaning to XML elements and attributes. This becomes crucial in an array of applications ranging over semantic-aware query rewriting, semantic document clustering and classification, schema matching, as well as blog analysis and event detection in social networks and tweets. Most existing approaches in this context: i) ignore the problem of identifying ambiguous XML nodes, ii) only partially consider their structural relations/context, iii) use syntactic information in processing XML data regardless of the semantics involved, and iv) are static in adopting fixed disambiguation constraints thus limiting user involvement. In this paper, we provide a new XML Semantic Disambiguation Framework titled XSDF designed to address each of the above motivations, taking as input: an XML document and a general purpose semantic network, and then producing as output a semantically augmented XML tree made of unambiguous semantic concepts. Experiments demonstrate the effectiveness of our approach in comparison with alternative methods. Categories and Subject Descriptors General Terms Algorithms, Measurement, Performance, Design, Experimentation. Keywords XML semantic-aware processing, a m b i g u i t y d e g r e e , s p h e r e neighborhood, XML context vector, semantic network, semantic disambiguation

    Une plateforme pour l'analyse de matériaux par faisceaux d'ions à ARRONAX : Etude de l'effet d'humidité sur les échantillons

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    International audienceQuantification of soil pollution with method based on X-ray detection like X-Ray Fluorescence(XRF) suffers of multiple bias (moisture, surface state) especially when it's used for insituanalysis using portable-XRF. In order to study the effect of moisture on the results of ananalysis performed using X-Ray, we have performed studies using high energy PIXE/PIGE atthe ARRONAX. Samples were made of sand of different type. High energy PIXE/PIGE allowsus to avoid bias from surface state and to focus on moisture effect. It also allows to assessthe chemical composition of the sample. Results show a different behavior for each elementpresent in volcanic sand.</p

    Full field modeling of recrystallization and grain growth thanks to a level set approach: towards modeling by industry

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    International audienceMetal forming modeling can be predictive only if the strain rate, strain and temperature dependency of the flow behaviour are correctly described. The mechanical properties and behaviour of metallic materials mainly depends on the content and structure of dislocation network, this points out the need to incorporate microstructure concepts into the numerical models. The goal is to correctly describe the main physical mechanisms occurring in metals during thermomechanical processes i.e. work-hardening, recovery, grain boundary migration, nucleation and grain growth related to dynamic, static or metadynamic recrystallization. Macroscopic and homogenized models are widely used in the industry, mainly due to their low computational cost. If this mean field framework is quite convenient, it can be synonymous, for a given material, with a large amount of experiments with advanced laboratory devices. Moreover, the homogenization of the microstructure does not permit to capture some very local phenomena

    Implementation, availability and regulatory status of an OECD accepted Reconstructed Human Epidermis model in Brazil

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    Introduction: In 2014, Brazil has joined the growing list of countries to ban cosmetic products from being tested on animal models. The new legislation comes into force in 2019. As a result, the interest for validated alternative testing methods for safety assessment has been increasing in academia, industry and associations. However, the lack of specific legislation on the use of biological material of human origin for toxicological tests makes the access to alternative in vitro models difficult. Furthermore, importation to Brazil is not possible on timely manner. Method: In this article, we report the implementation process of a Reconstructed Human Epidermis (SkinEthicℱ RHE), an alternative model internationally accepted by OECD, through a technology transfer from EPISKINÂź Lyon to Brazil. Regulatory evolution has been motivating the implementation and wide use of alternative methods to animal testing in several industry segments including cosmetic and pharmaceutical. Results: Protocol has been shown to be robust and highly reproducible. Quality control parameters (histological analysis, barrier function test and tissue viability) were performed on 24 batches assembled in Brazil. SkinEthicℱ RHE model use allows the full replacement of animal test methods for skin hazards identification. It has regulatory acceptance for several toxicological endpoints, such as the Draize test for skin irritation and corrosion. It allows the reduction and refining of pre-clinical protocols through tiered strategies. Implementation of SkinEthicℱ RHE protocol is just a first and important step towards a new approach of toxicological safety testing in Brazil. Conclusion: The implementation was successfully done and reported here. However, in order to follow completely the new legislation up to 2019, the availability of validated models is essential. Quality control tests done on RHE batches produced in Brazil demonstrate that the model met OECD acceptance criteria and therefore can be used for reliable prediction of irritation and corrosion classification.TÍTULO PT: Implementação, disponibilidade e contexto regulatĂłrio de um modelo de Epiderme Humana ReconstruĂ­da no Brasil aceito pela OECDIntrodução: Em 2014, o Brasil aderiu Ă  crescente lista de paĂ­ses a banir testes de produtos cosmĂ©ticos em modelos animais. A nova legislação entra em vigor em 2019. Como resultado, o interesse em mĂ©todos de testes alternativos validados para avaliação de segurança tem aumentado na academia, indĂșstria e associaçÔes. No entanto, a falta de legislação especĂ­fica sobre o uso de material biolĂłgico de origem humana para testes toxicolĂłgicos dificulta o acesso aos modelos alternativos in vitro. AlĂ©m disso, a importação no Brasil nĂŁo Ă© possĂ­vel em tempo hĂĄbil. MĂ©todo: Neste artigo, relatamos o processo de implementação de um modelo de Epiderme Humana ReconstruĂ­da (SkinEthicℱ RHE) internacionalmente aceito pela OECD, atravĂ©s de uma transferĂȘncia tecnolĂłgica da Episkin Lion para o Brasil, bem como discutimos a evolução regulatĂłria que tem motivado a implementação e a ampla utilização de mĂ©todos alternativos Ă  experimentação animal em diversos segmentos alĂ©m do cosmĂ©tico e farmacĂȘutico. Resultados: O protocolo de fabricação dos tecidos mostrou-se robusto e altamente reprodutĂ­vel, considerando os parĂąmetros de controle de qualidade (anĂĄlise histolĂłgica, função barreira e viabilidade tecidual) analisados em 24 lotes fabricados no Brasil. ConclusĂ”es: A implementação do modelo SkinEthicℱ RHE Ă© apenas um primeiro e importante passo em direção a uma nova abordagem para testes de segurança toxicolĂłgica no Brasil, realizada com ĂȘxito e aqui relatada. No entanto, para seguir plenamente a nova legislação atĂ© 2019, a disponibilidade de modelos validados Ă© essencial. Os testes de controle de qualidade realizados nos lotes RHE produzidos no Brasil demonstram que o modelo atende aos critĂ©rios de aceitação da OCDE e, portanto, pode ser usado para uma previsĂŁo confiĂĄvel de irritação e classificação de compostos corrosivos

    The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

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    Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase&nbsp;1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation&nbsp;disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age&nbsp; 6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score&nbsp; 652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc&nbsp;= 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N&nbsp;= 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in&nbsp;Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in&nbsp;Asia&nbsp;and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

    COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

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    Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≀ 18 years: 69, 48, 23; 85%), older adults (≄ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P &lt; 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

    Représentation Sémantique de Corpus de Documents HétérogÚnes pour un ModÚle de Recherche d'Information Novateur : Application au Domaine du Bùtiment

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    The recent advances of Information and Communication Technology (ICT) have resulted in the development of several industries. Adopting semantic technologies has proven several benefits for enabling a better representation of the data and empowering reasoning capabilities over it, especially within an Information Retrieval (IR) application. This has, however, few applications in the industries as there are still unresolved issues, such as the shift from heterogeneous interdependent documents to semantic data models and the representation of the search results while considering relevant contextual information. In this thesis, we address two main challenges. The first one focuses on the representation of the collective knowledge embedded in a heterogeneous document corpus covering both the domain-specific content of the documents, and other structural aspects such as their metadata, their dependencies (e.g., references), etc. The second one focuses on providing users with innovative search results, from the heterogeneous document corpus, helping the users in interpreting the information that is relevant to their inquiries and tracking cross document dependencies.To cope with these challenges, we first propose a semantic representation of a heterogeneous document corpus that generates a semantic graph covering both the structural and the domain-specific dimensions of the corpus. Then, we introduce a novel data structure for query answers, extracted from this graph, which embeds core information together with structural-based and domain-specific context. In order to provide such query answers, we propose an innovative query processing pipeline, which involves query interpretation, search, ranking, and presentation modules, with a focus on the search and ranking modules.Our proposal is generic as it can be applicable in different domains. However, in this thesis, it has been experimented in the Architecture, Engineering and Construction (AEC) industry using real-world construction projects.Les avancĂ©es rĂ©centes des Technologies de l'Information et de la Communication (TIC) ont entraĂźnĂ© des transformations radicales de plusieurs secteurs de l'industrie. L'adoption des technologies du Web SĂ©mantique a dĂ©montrĂ© plusieurs avantages, surtout dans une application de Recherche d'Information (RI) : une meilleure reprĂ©sentation des donnĂ©es et des capacitĂ©s de raisonnement sur celles-ci. Cependant, il existe encore peu d’applications industrielles car il reste encore des problĂšmes non rĂ©solus, tels que la reprĂ©sentation de documents hĂ©tĂ©rogĂšnes interdĂ©pendants Ă  travers des modĂšles de donnĂ©es sĂ©mantiques et la reprĂ©sentation des rĂ©sultats de recherche accompagnĂ©s d'informations contextuelles.Dans cette thĂšse, nous abordons deux dĂ©fis principaux. Le premier dĂ©fi porte sur la reprĂ©sentation de la connaissance relative Ă  un corpus de documents hĂ©tĂ©rogĂšnes couvrant Ă  la fois le contenu des documents fortement liĂ© Ă  un domaine mĂ©tier ainsi que d'autres aspects liĂ©s Ă  la structure de ces documents tels que leurs mĂ©tadonnĂ©es, les relations inter et intra-documentaires (p. ex., les rĂ©fĂ©rences entre documents ou parties de documents), etc. Le deuxiĂšme dĂ©fi porte sur la construction des rĂ©sultats de RI, Ă  partir de ce corpus de documents hĂ©tĂ©rogĂšnes, aidant les utilisateurs Ă  mieux interprĂ©ter les informations pertinentes de leur recherche surtout quand il s'agit d'exploiter les relations inter/intra-documentaires.Pour faire face Ă  ces dĂ©fis, nous proposons tout d'abord une reprĂ©sentation sĂ©mantique du corpus de documents hĂ©tĂ©rogĂšnes Ă  travers un modĂšle de graphe sĂ©mantique couvrant Ă  la fois les dimensions structurelle et mĂ©tier du corpus. Ensuite, nous dĂ©finissons une nouvelle structure de donnĂ©es pour les rĂ©sultats de recherche, extraite Ă  partir de ce graphe, qui incorpore les informations pertinentes directes ainsi qu'un contexte structurel et mĂ©tier. Afin d'exploiter cette nouvelle structure dans un modĂšle de RI novateur, nous proposons une chaĂźne de traitement automatique de la requĂȘte de l'utilisateur, allant du module d'interprĂ©tation de requĂȘte, aux modules de recherche, de classement et de prĂ©sentation des rĂ©sultats. Bien que nous proposions une chaĂźne de traitement complĂšte, nos contributions se focalisent sur les modules de recherche et de classement.Nous proposons une solution gĂ©nĂ©rique qui peut ĂȘtre appliquĂ©e dans diffĂ©rents domaines d'applications mĂ©tiers. Cependant, dans cette thĂšse, les expĂ©rimentations ont Ă©tĂ© appliquĂ©es au domaine du BĂątiment et Travaux Publics (BTP), en s'appuyant sur des projets de construction
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